Ryszard Palka

Design optimization of a permanent-magnet excited synchronous machine for electrical automobiles

The paper deals with the automated optimal design of a new synchronous motor particularly suitable for electric vehicles. Identifying the shape of rotor pole and excitation magnets, minimizing the mass/volume and simultaneously maxi- mizing the torque, is the main design goal. The formulation of this problem in terms of a bi-objective optimal shape design problem possibly stimulates the identification of unexplored solutions of practical significance.

Low Cogging Torque Design of Permanent Magnet Machine Using Modified Multi-Level Set Method With Total Variation Regularization

This paper proposes a topology optimization method, which allows to design a permanent magnet (PM) excited machine with improved high-speed features, incorporating the topological gradient into the multi-level set method with total variation regularization. It involves the design of both the stator and the rotor, the shape of which has a predominant impact on the mechanical and electric features of a PM machine. The concept of the topological gradient is incorporated for the nucleation of new holes in the distribution of level sets. The essential advantage of the proposed method is its ability to handle topology change on a fixed mesh and its flexibility in terms of shape changing that leads to efficient computational schemes. Finally, 2/3-D models are developed and deeply analyzed to indicate that the applied method leads to a significant reduction of both the cogging torque and the amount of higher back EMF harmonics.

Optimization of the MIT Field Exciter by a Multiobjective Design

This paper deals with the shape design of the excitation unit of a magnetic induction tomography (MIT) system by means of a procedure of multiobjective design. As a result of the proposed method, a set of optimal geometries of the basic excitation structure was found.

Topology optimization of rotor poles in a permanent-magnet machine using level set method and continuum design sensitivity analysis

– In this paper, a numerical approach to the topology optimization is proposed to design the permanent magnet excited machines with improved high-speed features. For this purpose the modified multi-level set method (MLSM) was proposed and applied to capture the shape of rotor poles on the fixed mesh using FE analysis. The paper aims to discuss these issues. , – This framework is based on theories of topological and shape derivative for the magnetostatic system. During the iterative optimization process, the shape of rotor poles and its evolution is represented by the level sets of a continuous level set function f. The shape optimization of the iron and the magnet rotor poles is provided by the combining continuum design sensitivity analysis with level set method. , – To obtain an innovative design of the rotor poles composed of different materials, the modified MLSM is proposed. An essential advantage of the proposed method is its ability to handle a topology change on a fixed mesh by the nucleating a small hole in design domain that leads to more efficient computational scheme then standard level set method. , – The proposed numerical approach to the topology design of the 3D model of a PM machine is based on the simplified 2D model under assumption that the eddy currents in both the magnet and iron parts are neglected. , – The novel aspect of the proposed method is the incorporation of the Total Variation regularization in the MLSM, which distribution is additionally modified by the gradient derivative information, in order to stabilize the optimization process and penalize oscillations without smoothing edges.

Design of Hybrid Excited Synchronous Machine for Electrical Vehicles

This paper deals with the optimal design of a new synchronous motor particularly suitable for electric vehicles. The unique advantage of this motor is its possibility to realize field weakening at high speeds, which is the most important demand for such drives. The main design goal is to identify the dimensions of certain crucial regions of the machine in order to avoid saturation of the iron and to minimize the mass to volume ratio, while simultaneously maximizing the torque. The originality of the contribution is manifold: formulating the design problem in multiobjective terms, solving it by means of evolutionary computing, solving the associated direct problem based on a three-dimensional finite element analysis (3-D-FEA) field model, considering a reduced set of design variables by means of response surface method, referring to a real-life problem.

Analysis of electromagnetic field and power losses in three phase gas insulated cable

The following paper presents the electro-magnetic field distribution in a three phase gas insulated cable. Formulas for calculation of power losses in the cable sheath are also given. Applying the separation-of-variables method it was possible to obtain general fi - nal dependences. With the help of a computer, theoretical considerations were illustrated by numerical calculations.

Synthesis of magnetic fields

The paper deals with some problems of magnetic fields synthesis, depending on determination of the current density distribution, which generates the required magnetic field in the investigated region. Such problems can be reduced to the linear, or nonlinear Fredholm integral equations of the first kind, or to the set of these equations. Fredholm integral equation of the first kind belongs to the class of the ill-posed problems, and for its solving the method of regularisation has been used. In the paper there are given some useful results of synthesis of magnetic fields in few practical configurations.

Synthesis of magnetic fields by optimization of the shape of areas and source distributions

ContentsThe paper deals with a practical method for the synthesis of two-dimensional magnetic fields. The proposed algorithm makes it possible to determine the optimal structure of areas and optimal source distribution which generate the required magnetic fields. The main idea of this algorithm is based on the application of a modified gradient method for solving the overdetermined, nonlinear system of algebraic equations obtained by the finite element method. Numerical calculations performed in 5 examples demonstrate possible applications of the proposed method.ÜbersichtDie Arbeit behandelt eine praktische Methode zur Synthese von zweidimensionalen Magnetfeldern. Das vorgeschlagene Verfahren ermöglicht die Berechnung der optimalen Form von Gebieten und optimalen Quellenverteilungen zur Erzeugung vorgegebener Magnetfelder. Die Grundidee des Berechnungsverfahrens basiert auf der Anwendung einer modifizierten Gradientenmethode zur Lösung von nichtlinearen, überbestimmten Gleichungssystemen, die mit der Methode der finiten Elemente entwickelt wurden. Numerische Berechnungen von 5 Beispielen illustrieren die Anwendungsbreite der vorgeschlagenen Methode.

Evaluation of the magnetic field – high temperature superconductor interactions

To describe the wide range of possible applications of high temperature superconductors (HTSCs) (e.g. magnetic bearings, levitation systems or electrical machines) several appropriate calculation algorithms have been developed. They determine the force interaction between a superconductor and any even multidimensional magnetic field excitation system. Especially good agreements between experiments and computed results have been obtained for the Vector‐Controlled Model, which seems to be the best approximation of the macroscopic superconductivity behaviour. The validation of this model by means of measurements makes it a powerful tool for the design and optimisation of any HTSC application in the field of force generation. It can be used not only for the designing of levitation applications, but also to help the understanding of the flux penetration, flux trapping and magnetisation of bulk superconductors in non‐uniform magnetic fields. By means of this model, the force interaction between superconductors and external magnetic fields for practical multi‐polar configurations, e.g. superconducting levitation systems or inherently stable superconducting bearings has been determined. Furthermore, the time dependency of the forces taking flux flow and flux creep into account, can be considered.

Hybrid excited synchronous machine with flux control possibility

The paper presents simulation and experimental results of an Electric Controlled Permanent Magnet Synchronous (ECPMS) machine that offers an extended magnetic field control capability which makes it suitable for battery electric vehicle drives. Rotor, stator and additional direct current supplied coil of the machine have been analyzed in detail. Control and power supply systems of the machine have been presented. Influence of the additional excitation on the machine performance has also been discussed.